1. Field of the Invention
This invention relates to production of methanol from solid carbonaceous material such as oil shale, coal and the like. More particularly, the invention relates to production of methanol utilizing a feed gas obtained by air-blowing coal. The feed gas contains carbon oxides which are converted to methanol by catalytic hydrogenation.
Most coal gasification processes utilize an oxygen-blown gasifier. The amount of oxygen required for this process is large, and accordingly a costly air separation plant is necessary.
Air-blown gasifiers, not requiring an air separation plant, are available, but the gas from air-blown gasifiers has a high (about 50 volume percent) nitrogen content. Reactors for making methanol from gas obtained from coal gasifiers generally do not operate efficiently if the feed gas has a nitrogen content above about 25 volume percent. For this reason, feed gas from air-blown gasifiers has not been successfully used to produce methanol.
2. Description of the Prior Art
U.S. Pat. No. 1,788,170 describes a process for producing methanol using feed gas which is apparently from an air-blown gasifier. However, no provision is made in the reference process for reducing the nitrogen content to the reactor.
British Pat. No. 266,405 discloses the formation of methanol by catalytic conversion of a feed gas made by coal gasification with air so that the feed gas contains about 50 percent nitrogen. The reference further discloses removal of a portion of the gas from the conversion loop to adjust the composition of the gas stream.